Walker navigation device and program

ABSTRACT

A pedestrian navigation device ( 10 A) of this invention comprises a position information reception portion ( 12 ), which obtains current position information from a GPS ( 20 ); a position information analysis portion ( 13 ), which analyzes current position information received by the position information reception portion ( 12 ) and calculates the current position; a MAPDB (Map Data Base) ( 14 ), which stores map information; a central processing portion ( 11 ), which calculates current position display information, based on the current position calculated by the position information analysis portion ( 13 ) and on map information stored in the MAPDB ( 14 ); a display portion, which displays current position display information calculated by the central processing portion ( 11 ); and an input portion ( 16 ), which inputs route search conditions and issues instructions to begin navigation. By this means, a pedestrian navigation device is provided which, when navigating a pedestrian route, is able to accurately detect the direction of advance through judgment of stops and suppression of meandering.

TECHNICAL FIELD

This invention relates to a pedestrian navigation device and program fornavigation of the route of a pedestrian. In particular, this inventionrelates to a pedestrian navigation device and program capable ofaccurately detecting the direction of advance through judgment of stopsand suppression of meandering.

BACKGROUND ART

In the prior art, there are navigation devices, portable telephones andsimilar which provide navigation of routes for vehicles and personsusing position information from the GPS (Global Positioning System).

For example, Japanese Patent Laid-open No. 8-334337 discloses a currentposition calculation device capable of returning to an initial value atravel distance coefficient, used to calculating travel distances, whichis corrected in accordance with vehicle travel.

In this current position calculation device, an MPU multiplies thenumber of output pulses from a vehicle velocity sensor, counted by acounter, by a travel distance coefficient to calculate the traveldistance of the vehicle, and estimates the traveled road being traveledby the vehicle and the current position of the vehicle on the traveledroad based on map data stored on a CD-ROM, the vehicle direction ofadvance determined from measured values of an angular velocity sensorand bearing sensor, and the distance traveled by the vehicle. Here, thetravel distance coefficient is dynamically corrected according to thedifference between the direction of the traveled road at the estimatedcurrent position and the direction of advance of the vehicle. When theMPU is instructed by a switch to correct the estimated current position,the travel distance coefficient is returned to an initial value inresponse to the instruction.

Thus by returning to an initial value as necessary a travel distancecoefficient which is used to calculate travel distances, and which iscorrect as the vehicle travels, the current position of the vehicle canbe accurately detected.

There is a radial error of approximately 10 meters in the positioninformation from the GPS; by means of a current position calculationdevice such as that described in Japanese Patent Laid-open No. 8-334337and ordinary vehicle navigation systems, position information when thereis motion equal to or greater than a prescribed distance exceeding thiserror is used to detect the current position.

DISCLOSURE OF THE INVENTION

However, when the velocity of motion is slow, as in the case of apedestrian, if position is displayed at prescribed time intervals, thedisplay is such as that shown in FIG. 9. That is, when the actual routeof movement is “a→b→c→d→e”, the displayed route is “a→b′→c′→d′→e′(meandering route)”, and the display is not accurate.

Further, in the case of a conventional navigation device, when apedestrian [begins to] move after having stopped, even if the actualroute of movement is “a0→a8” as shown in FIG. 10, if the route isdisplayed at prescribed time intervals, the route“a0→a1→a2→a3→a4→a5→a6→a7→a8” is displayed, and the stopped state cannotbe accurately displayed.

Hence one object of this invention is to provide a pedestrian navigationdevice and program capable of accurately detecting the direction ofadvance, through judgment of stops and suppression of meandering, whennavigating the route of a pedestrian.

In order to attain this object, the pedestrian navigation device of afirst aspect of the invention is a pedestrian navigation device whichnavigates the route of a pedestrian, comprising position informationreception means for obtaining current position information; positioninformation analysis means for analyzing current position informationreceived by the position information reception means and calculating thecurrent position; map information storage means for storing mapinformation; central processing means for calculating current positiondisplay information, based on the current position calculated by thecurrent position analysis means, and on map information stored by themap information storage means; and display means for displaying thecurrent position display information calculated by the centralprocessing means; and characterized in that the central processing meanshas pedestrian history information comprising a reference direction aindicating the direction of past routes of movement and a referencedistance β indicating a prescribed distance, and that, when the currentposition at the start of navigation is reference point a0 and thecurrent position ai after a prescribed time is received from theposition information analysis means, [the central processing means]calculates the distance La0ai between the reference point a0 and thecurrent position ai, and whenβ>La0ai   (1)corrects the current position ai in the direction of the referencedirection a and calculates the current position display information, butwhenβ≦La0ai   (2)corrects the current position ai in the direction of the referencedirection a and calculates the current position display information, andin addition takes the corrected position of the current position ai tobe the new reference point, and takes the direction from the referencepoint a0 to the new reference point to be the new reference direction α.

Also, in order to attain the above object, the pedestrian navigationdevice of a second aspect of the invention is a pedestrian navigationdevice which navigates the route of a pedestrian, comprising positioninformation reception means for obtaining current position information;position information analysis means for analyzing current positioninformation received by the position information reception means andcalculating the current position; map information storage means forstoring map information; central processing means for calculatingcurrent position display information, based on the current positioncalculated by the current position analysis means, and on mapinformation stored by the map information storage means; and displaymeans for displaying the current position display information calculatedby the central processing means; and characterized in that the centralprocessing means receives the current position ai from the positioninformation analysis means at prescribed intervals, and when theabsolute values of the difference between the direction angle Ai fromthe preceding current position ai-1 to the present current position aiand the reference angle A is such thatα0 (tolerance angle)≦|A−Ai|  (3)calculates the current position display information from the currentposition ai, and takes the direction angle Ai to be the new referenceangle A.

Also, in order to attain the above object, the pedestrian navigationdevice of a third aspect of the invention is a pedestrian navigationdevice which navigates the route of a pedestrian, comprising positioninformation reception means for obtaining current position information;position information analysis means for analyzing current positioninformation received by the position information reception means andcalculating the current position; map information storage means forstoring map information; central processing means for calculatingcurrent position display information, based on the current positioncalculated by the current position analysis means, and on mapinformation stored by the map information storage means; and displaymeans for displaying the current position display information calculatedby the central processing means; and characterized in that the centralprocessing means takes the current position at the start of navigationas the reference point a0, receives the current position ai atprescribed intervals from the position information analysis means,calculates the distance La0ai between the reference position a0 and thecurrent position ai, and whenβ(reference distance)>La 0 ai   (4)

calculates the current position display information from the currentposition ai, but whenβ(reference distance)≦La 0 ai   (5)

calculates the current position display information from the currentposition ai, and in addition takes the current position ai to be the newreference point, and takes the direction from the previous referencepoint a0 to the new reference point ai to be the new reference directionα.

Here, the central processing means takes the current position at thetime navigation is started to be the reference point a0, receives thecurrent position ai at prescribed intervals from the positioninformation analysis means, and calculates the distance La0ai betweenthe reference point a0 and the current position ai; ifβ(reference distance)>La 0 ai   (4)

then the current position display information is calculated from thecurrent position ai, but ifβ(reference distance)≦La 0 ai   (5)

then it is also possible to calculate the current position displayinformation from the current position ai, and in addition to take thecurrent position al calculated next after the reference point a0 to bethe new reference point, and to take the direction from the referencepoint a0 to the current position ai to be the new reference direction α.

Also, in order to attain the above object, the pedestrian navigationdevice of a fourth aspect of the invention is a pedestrian navigationdevice which navigates the route of a pedestrian, comprising positioninformation reception means for obtaining current position information;position information analysis means for analyzing current positioninformation received by the position information reception means andcalculating the current position; map information storage means forstoring map information; central processing means for calculatingcurrent position display information, based on the current positioncalculated by the current position analysis means, and on mapinformation stored by the map information storage means; and displaymeans for displaying the current position display information calculatedby the central processing means; and characterized in that the centralprocessing means has a reference direction a indicating the direction ofthe past movement route and a prescribed tolerance angle γ, takes thecurrent position at the time of the start of navigation to be thereference point a0, and upon receiving the current position ai aprescribed time later from the position information analysis means,calculates the direction a0→ai [from] the reference point a0 to thecurrent position ai, and (a) if the direction a0→ai is equivalent to thereference direction a within the range of the tolerance angle y, usesthe current position display information calculated using the referencepoint a0 without modification, but (b) if the direction a0→ai is notequivalent to the reference direction a within the range of thetolerance angle γ, calculates the current position display informationusing the current position ai, and in addition takes the correctedposition of the current position ai to be the new reference point, andtakes the direction from the reference point a0 to the new referencepoint ai to be the new reference direction α.

Also, in order to attain the above object, the pedestrian navigationdevice of a fifth aspect of the invention is a pedestrian navigationdevice which navigates the route of a pedestrian, comprising positioninformation reception means for obtaining current position information;position information analysis means for analyzing current positioninformation received by the position information reception means andcalculating the current position; map information storage means forstoring map information; central processing means for calculatingcurrent position display information, based on the current positioncalculated by the current position analysis means, and on mapinformation stored by the map information storage means; display meansfor displaying the current position display information calculated bythe central processing means; and direction measurement means formeasuring the direction of advance; and characterized in that thecentral processing means takes the current position at the time of thestart of navigation to be the reference point a0, and upon receiving thecurrent position a1 a prescribed time later from the positioninformation analysis means, corrects the current position a1 using thedirection of advance measured by the direction measurement means andcalculates current position display information, and in addition takesthe corrected current position a1 to be the new reference point.

Also, in order to attain the above object, the pedestrian navigationdevice of a sixth aspect of the invention is a pedestrian navigationdevice which navigates the route of a pedestrian, comprising positioninformation reception means for obtaining current position information;position information analysis means for analyzing current positioninformation received by the position information reception means andcalculating the current position; map information storage means forstoring map information; central processing means for calculatingcurrent position display information, based on the current positioncalculated by the current position analysis means, and on mapinformation stored by the map information storage means; display meansfor displaying the current position display information calculated bythe central processing means; and direction measurement means formeasuring the direction of advance; and characterized in that thecentral processing means takes the current position at the time of thestart of navigation to be the reference point a0, and upon receiving thecurrent position ai a prescribed time later from the positioninformation analysis means, calculates the direction a0→ai [from] thereference point a0 to the current position ai, and (a) if the directiona0→ai is outside the range of the tolerance angle γ from the directionof advance measured by the direction measurement means, uses the currentposition display information calculated using the reference point a0without modification, but (b) if the direction a0→ai is within the rangeof the tolerance angle γ from the direction of advance measured by thedirection measurement means, calculates the current position displayinformation using the current position ai, and in addition takes thecorrected position of the current position ai to be the new referencepoint.

Here, the direction measurement means can be an electronic compass or agyrosensor.

The position information reception means can obtain current positioninformation from the GPS (Global Positioning System).

In order to attain the above object, a program of this invention is aprogram which causes a portable terminal to navigate the route of apedestrian, and is characterized in realizing the functions of theabove-described pedestrian navigation devices in the portable terminal.

By correcting position information using a reference distance, referencedirection, tolerance angle, electronic compass, gyrosensor and similar,the direction of advance can be detected accurately through judgment ofstops and suppression of meandering when navigating the route of apedestrian.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows one example of a pedestrian navigation device of thisinvention;

FIG. 2 shows a route display by a pedestrian navigation device of thisinvention;

FIG. 3 shows a route display by a pedestrian navigation device of thisinvention;

FIG. 4 shows a route display by a pedestrian navigation device of thisinvention;

FIG. 5 shows a route display by a pedestrian navigation device of thisinvention;

FIG. 6 shows one example of a pedestrian navigation device of thisinvention;

FIG. 7 shows a route display by a pedestrian navigation device of thisinvention;

FIG. 8 shows a route display by a pedestrian navigation device of thisinvention;

FIG. 9 shows a route display by a conventional navigation device; and,

FIG. 10 shows a route display by a conventional navigation device.

BEST MODE FOR CARRYING OUT THE INVENTION

Below, aspects of a pedestrian navigation device and program of theinvention are explained, referring to the drawings.

Of course the scope of this invention is not limited to these aspects.

FIG. 1 shows one example of a pedestrian navigation device of thisinvention. In FIG. 1, the pedestrian navigation device 10A comprises aposition information reception portion 12, which obtains currentposition information from the GPS (Global Positioning System) 20; aposition information analysis portion 13, which analyzes currentposition information received by the position information receptionportion 12 and calculates the current position; a MAPDB (Map Data Base)14, which stores map information; a central processing portion 11, whichcalculates current position display information based on the currentposition calculated by the position information analysis portion 13 andon map information stored in the MAPDB 14; a display portion 15, whichdisplays current position display information calculated by the centralprocessing portion 11; and an input portion 16, which inputs routesearch conditions and instructions to begin navigation.

FIG. 2 shows a route display by a pedestrian navigation device of thisinvention. In FIG. 1 and FIG. 2, the route of a pedestrian is displayedon the display portion 15, in accordance with input of the route searchconditions and an instruction to begin navigation from the input portion16. Here, the current position at the start of navigation is taken to bethe initial reference point a0. The current position ai after a certaintime has elapsed is calculated by receiving current position informationfrom the GPS by the position information reception portion 12, andanalyzing the current position information in the position informationanalysis portion 13; this current position is passed to the centralprocessing portion 11.

The central processing portion 11 has pedestrian history information,including a reference direction a which indicates the direction of thepast movement route and a reference distance β which indicates aprescribed distance. When the current position ai after a prescribedtime ti (seconds) is received from the position information analysisportion 13, the distance La0ai between the reference point a0 andcurrent position ai is calculated, and whenβ>La0ai   (1)

the current position ai is corrected in the direction of the referencedirection α and the current position display information is calculated,but whenβ≦La0ai   (2)

the current position ai is corrected in the direction of the referencedirection α and the current position display information is calculated,and in addition the corrected position of the current position ai istaken to be the new reference point, and the direction from thereference point a0 to the new reference point is taken to be the newreference direction α.

In FIG. 2, each corrected position is at a position descended along aperpendicular line from the current position ai (i=1 to 4) on thestraight line in the reference direction α. Here, positions advanced bythe distance “ai-1 to ai” from the corrected position ai-1 in the αdirection can be called corrected positions. In FIG. 2, the correctedposition of the current position a4 becomes the new reference point.

FIG. 3 shows a route display by the pedestrian navigation device of theinvention shown in FIG. 1. In FIG. 1 and FIG. 3, the route of thepedestrian is displayed on the display portion 15 according to input ofroute search conditions and an instruction to start navigation from theinput portion 16. Here, the current position at the time of the start ofnavigation is taken to be the initial reference point a0. The currentposition ai after a certain time has elapsed is calculated by receivingcurrent position information from the GPS using the position informationreception portion 12 and analyzing the current position informationusing the position information analysis portion 13, and is then passedto the central processing portion 11.

Here, the central processing means calculates the distance La0ai fromthe reference point a0 to the current position ai, and whenβ(reference distance)>La 0 ai   (4)

calculates the current position display information from the currentposition ai, but whenβ(reference distance)≦La 0 ai   (5)

calculates the current position display information from the currentposition ai, and in addition takes the current position ai to be the newreference point, and takes the direction from the previous referencepoint a0 to the new reference point ai to be the new reference directionα.

Here, the reference direction α can also be used to correct the currentposition ai in the direction of the reference direction α, beforecalculating the current position display information.

Hence as shown in FIG. 3, the display route can be displayed as“a0→a1→a2→a3→a4”, and can also be displayed as “a0→b→c→d→e”. In FIG. 3,the current position a4 or the corrected position thereof e becomes thenew reference point, and the direction from the previous reference pointa0 to the new reference point a4 or e becomes the new referencedirection α.

FIG. 4 shows a route display by the pedestrian navigation device of thisinvention of FIG. 1. In FIG. 1 and FIG. 4, the route of the pedestrianis displayed on the display portion 15 according to input of routesearch conditions and an instruction to start navigation from the inputportion 16. Here, the current position at the time of the start ofnavigation is taken to be the initial reference point a0. The currentposition ai after a certain time has elapsed is calculated by receivingcurrent position information from the GPS using the position informationreception portion 12 and analyzing the current position informationusing the position information analysis portion 13, and is then passedto the central processing portion 11.

Here, the central processing means receives the current position ai atprescribed intervals from the position information analysis portion 13,and when the absolute value of the difference between the directionangle Ai from the previous current position ai-1 to the present currentposition ai and the reference angle A is such thatα0 (tolerance angle)≧|A−Ai|  (3)

calculates the current position display information from the currentposition ai, and takes the direction angle Ai to be the new referenceangle A.

In FIG. 4, upon moving from a0 to a1, the initial reference angle A is“A=0”. Here, the absolute value (A1) of the difference between thedirection angle A1 from a0 to a1 and the reference angle A is within therange of the tolerance angle α, so that based on the current position a1and the map information stored in MABPDB 14, the current positiondisplay information is calculated, and the direction angle A1 becomesthe reference angle A. Then, when moving from a1 to a2, the referenceangle A is “A=A1”. Here, the absolute value of the difference betweenthe direction angle A2 from a1 to a2 and the reference angle A (=A1)(|A(=A1)−A2|) is within the range of the tolerance angle α, so thatbased on the current position a2 and map information stored in MAPDB 14,the current position display information is calculated, and thedirection angle A2 becomes the new reference angle A.

Next, when moving from a2 to a3, the reference angle A is “A=A2”. Here,the absolute value of the difference between the direction angle A3 froma2 to a3 and the reference angle A (=A2) (|A(=A2)−A3|) exceeds the rangeof the tolerance angle α, so that the data of the current position a3 isnot used, and the position is not displayed. When moving to a4, thereference angle A is “A=A2”, so that using the direction angle A4 froma2 to a4 and the reference angle A (=A2), the absolute value of thedifference (|A(=A2)−A4|) is compared with the tolerance angle α. Becausethe value (|A(=A2)−A4|) is within the range of the tolerance angle α,current position display information is calculated based on the currentposition a4 and map information stored in MAPDB 14, and the directionangle A4 is taken to be the new reference angle A. In this way, routedisplay is performed.

FIG. 5 shows a route display by the pedestrian navigation device of thisinvention of FIG. 1. In FIG. 1 and FIG. 5, the route of the pedestrianis displayed on the display portion 15 according to input of routesearch conditions and an instruction to start navigation from the inputportion 16. Here, the current position at the time of the start ofnavigation is taken to be the initial reference point a0. The currentposition ai after a certain time has elapsed is calculated by receivingcurrent position information from the GPS using the position informationreception portion 12 and analyzing the current position informationusing the position information analysis portion 13, and is then passedto the central processing portion 11.

Here, the central processing means has a reference direction αindicating the direction of the past movement route and a prescribedtolerance angle γ, and when receiving the current position ai from theposition information analysis means after a prescribed time t (seconds),calculates the direction a0→ai from the reference point a0 to thecurrent position ai; and (a) if the direction a0→ai is outside the rangeof the tolerance angle γ from the reference direction α, the currentposition display information is calculated using the reference point a0without modification, and in addition the corrected current position aiis taken to be the new reference point, but (b) if the direction a0→aiis within the range of the tolerance angle γ from the referencedirection α, the current position display information is calculatedusing the current position ai, and in addition the corrected position ofthe current position ai is taken to be the new reference point, and thedirection from the previous reference point a0 to the new referencepoint ai is taken to be the new reference direction α.

In FIG. 5, if the pedestrian is stopped at reference point a0, theposition information calculated using current position information fromthe GPS is a1 to a7. At this time, the direction a0→ai (i=1 to 7) isoutside the range of the tolerance angle γ from the reference directionα, so that the position information a1 to a7 is not used in calculatingthe current position display information, and is not displayed as routeinformation. Next, when the pedestrian moves and the positioninformation a8 is calculated using current position information from theGPS, the direction a0→a8 is within the range of the tolerance angle γfrom the reference direction α, so that the position information a8 isused in calculating current position display information, and “a0→a8” isdisplayed as route information.

FIG. 6 shows one example of a pedestrian navigation device of thisinvention. In FIG. 6, the pedestrian navigation device 10B comprises aposition information reception portion 12, which obtains currentposition information from the GPS 20; a position information analysisportion 13, which analyzes current position information received by theposition information reception portion 12 and calculates the currentposition; a MAPDB (Map Data Base) 14, which stores map information; acentral processing portion 11, which calculates current position displayinformation based on the current position calculated by the positioninformation analysis portion 13 and on map information stored in theMAPDB 14; a display portion 15, which displays current position displayinformation calculated by the central processing portion 11; an inputportion 16, which inputs route search conditions and instructions tobegin navigation; and an electronic compass 17, which measures thedirection of advance. Here, in place of the electronic compass 17, agyrosensor may be used.

FIG. 7 shows a route display by the pedestrian navigation device of thisinvention in FIG. 6. In FIG. 6 and FIG. 7, the route of the pedestrianis displayed on the display portion 15 according to input of routesearch conditions and an instruction to start navigation from the inputportion 16. Here, the current position at the time of the start ofnavigation is taken to be the initial reference point a0. The currentposition ai after a certain time has elapsed is calculated by receivingcurrent position information from the GPS using the position informationreception portion 12 and analyzing the current position informationusing the position information analysis portion 13 to calculate thecurrent position, which is then passed to the central processing portion11.

The electronic compass 17 (or gyrosensor) detects the electronic compassdirection (reference direction α) indicating the direction of themovement route, and passes this to the central processing portion 11.The central processing portion 11, upon receiving the current positionai after a prescribed time ti (seconds) from the position informationanalysis portion 13, corrects the current position ai in the directionof the reference direction α to calculate current position displayinformation, and takes the corrected current position ai to be the newreference point.

In FIG. 7, the central processing portion 11, upon receiving the currentposition a1 after a prescribed time t1 (seconds) from the positioninformation analysis portion 13, corrects the current position a1 in theelectronic compass direction (the reference direction α) to calculatecurrent position display information, and takes the corrected currentposition information b of the current position ai to be the newreference point. Similarly, the corrected position information [values]c to e of the sequence of current positions a2 to a4 are used tocalculate current position display information.

FIG. 8 shows a route display by the pedestrian navigation device of thisinvention shown in FIG. 6. In FIG. 6 and FIG. 8, the route of thepedestrian is displayed on the display portion 15 according to input ofroute search conditions and an instruction to start navigation from theinput portion 16. Here, the current position at the time of the start ofnavigation is taken to be the initial reference point a0. The currentposition ai after a certain time has elapsed is calculated by receivingcurrent position information from the GPS using the position informationreception portion 12 and analyzing the current position informationusing the position information analysis portion 13, and is then passedto the central processing portion 11.

The electronic compass 17 (or gyrosensor) detects the electronic compassdirection (reference direction α ) indicating the direction of themovement route, and passes this to the central processing portion 11.The central processing portion 11 takes the current position at thestart of navigation to be the reference point a0, and upon receiving thecurrent position ai after a prescribed time ti (seconds) from theposition information analysis means, calculates the direction a0→ai fromthe reference point a0 to the current position ai; and (a) if thedirection a0→ai is outside the range of the tolerance angle γ from thedirection of advance measured by the direction measurement means, thecurrent position display information calculated using the referencepoint a0 is used without modification, but (b) if the direction a0→ai iswithin the range of the tolerance angle γ from the direction of advancemeasured by the direction measurement means, the current positiondisplay information is calculated using the current position ai, and inaddition the corrected position of the current position ai is taken tobe the new reference point.

In FIG. 8, when the pedestrian is stopped at the reference point a0, theposition information calculated using current position information fromthe GPS is a1 to a7. At this time, the direction a0→ai (i=1 to 7) isoutside the range of the tolerance angle γ from the electronic compassdirection (reference direction α ), so that the position information[values] a1 to a7 are not used to calculate current position displayinformation, and are not displayed as route information. Next, when thepedestrian moves and the position information a8 is calculated usingcurrent position information from the GPS, the direction a0→a8 is withinthe range of the tolerance angle γ from the electronic compass direction(reference direction α), so that the position information a8 is used incalculating the current position display information, and “a0→a8” isdisplayed as route information.

In the above, a pedestrian navigation device of this invention has beenexplained; but a portable telephone or other portable terminal can beprovided with a program for navigation of pedestrian routes, and such aprogram can realize the functions of the above-described pedestriannavigation device in a portable terminal.

As explained above, through a pedestrian navigation device and programof this invention, by using a reference distance, reference direction,tolerance angle, electronic compass, gyrosensor, and similar to correctposition information, the direction of advance can be detectedaccurately through judgment of stops and suppression of meandering whennavigating pedestrian routes.

1. A pedestrian navigation device for navigating the route of apedestrian, comprising: position information reception means forobtaining current position information; position information analysismeans for analyzing said current position information received by thesaid position information reception means and calculating the currentposition; map information storage means for storing map information;central processing means for calculating current position displayinformation, based on said current position calculated by said positioninformation analysis means, and on said map information stored by saidmap information storage means; and, display means for displaying saidcurrent position display information calculated by said centralprocessing means; and characterized in that said central processingmeans has pedestrian history information comprising a referencedirection α indicating the direction of a past movement route and areference distance β indicating a prescribed distance, takes the currentposition at the start of navigation to be reference point a0, and, uponreceiving the current position ai after a prescribed time from saidposition information analysis means, calculates the distance La0aibetween said reference point a0 and said current position ai, and whenβ>La0ai   (1) corrects said current position ai in the direction of saidreference direction α and calculates current position displayinformation, but whenβ≦La0ai   (2) corrects said current position ai in the direction of saidreference direction α and calculates current position displayinformation, and in addition takes the corrected position of saidcurrent position ai to be the new reference point, and takes thedirection from the previous reference point a0 to the new referencepoint to be the new reference direction α.
 2. A pedestrian navigationdevice for navigating the route of a pedestrian, comprising: positioninformation reception means for obtaining current position information;position information analysis means for analyzing said current positioninformation received by the said position information reception meansand calculating the current position; map information storage means forstoring map information; central processing means for calculatingcurrent position display information, based on said current positioncalculated by said position information analysis means, and on said mapinformation stored by said map information storage means; and, displaymeans for displaying said current position display informationcalculated by said central processing means; and characterized in thatsaid central processing means receives the current position ai from saidposition information analysis means at prescribed intervals, and whenthe absolute value of the difference between the direction angle Ai fromthe preceding current position ai-1 to the present current position aiand the reference angle A is such thatα0 (tolerance angle)≧|A−Ai|  (3) calculates current position displayinformation from said current position ai, and takes the direction angleAi to be the new reference angle A.
 3. A pedestrian navigation devicefor navigating the route of a pedestrian, comprising: positioninformation reception means for obtaining current position information;position information analysis means for analyzing said current positioninformation received by the said position information reception meansand calculating the current position; map information storage means forstoring map information; central processing means for calculatingcurrent position display information, based on said current positioncalculated by said position information analysis means, and on said mapinformation stored by said map information storage means; and, displaymeans for displaying said current position display informationcalculated by said central processing means; and characterized in thatsaid central processing means takes the current position at the start ofnavigation to be the reference point a0, receives the current positionai at prescribed intervals from said position information analysismeans, calculates the distance La0ai between said reference point a0 andthe current position ai, and whenβ(reference distance)>La 0 ai   (4) calculates current position displayinformation from said current position ai, but whenβ(reference distance)≦La 0 ai   (5) calculates current position displayinformation from said current position ai, and in addition takes saidcurrent position ai to be the new reference point, and takes thedirection from the previous reference point a0 to the new referencepoint ai to be the new reference direction α.
 4. The pedestriannavigation device according to claim 3, characterized in that saidcentral processing means takes the current position at the start ofnavigation to be the reference point a0, receives the current positionai at prescribed intervals from said position information analysismeans, calculates the distance La0ai between said reference point a0 andsaid current position ai, and whenβ(reference distance)>La 0 ai   (4) calculates current position displayinformation from said current position ai, but whenβ(reference distance)≦La 0 ai   (5) calculates current position displayinformation from said current position ai, and in addition takes thecurrent position a1 next calculated after said reference point a0 to bethe new reference point, and takes the direction from the previousreference point a0 to said current position ai to be the new referencedirection α.
 5. A pedestrian navigation device for navigating the routeof a pedestrian, comprising: position information reception means forobtaining current position information; position information analysismeans for analyzing said current position information received by thesaid position information reception means and calculating the currentposition; map information storage means for storing map information;central processing means for calculating current position displayinformation, based on said current position calculated by said positioninformation analysis means, and on said map information stored by saidmap information storage means; and, display means for displaying saidcurrent position display information calculated by said centralprocessing means; and characterized in that said central processingmeans has a reference direction α indicating the direction of a pastmovement route and a prescribed tolerance angle γ, takes the currentposition at the start of navigation to be reference point a0, and, uponreceiving the current position ai after a prescribed time from saidposition information analysis means, calculates the direction a0→ai fromsaid reference point a0 to said current position ai, and (a) if thedirection a0→ai is outside the range of the tolerance angle γ from thereference direction α, uses current position display informationcalculated using said reference point a0 without modification; but (b)if the direction a0→ai is within the range of the tolerance angle γ fromthe reference direction α, calculates current position displayinformation using said current position ai, and moreover takes thecorrected position of said current position ai to be the new referencepoint, and takes the direction from the previous reference point a0 tothe new reference point ai to be the new reference direction α.
 6. Apedestrian navigation device for navigating the route of a pedestrian,comprising: position information reception means for obtaining currentposition information; position information analysis means for analyzingsaid current position information received by the said positioninformation reception means and calculating the current position; mapinformation storage means for storing map information; centralprocessing means for calculating current position display information,based on said current position calculated by said position informationanalysis means, and on said map information stored by said mapinformation storage means; display means for displaying said currentposition display information calculated by said central processingmeans; and, direction measurement means for measuring the direction ofadvance; and characterized in that said central processing means takesthe current position at the start of navigation to be reference pointa0, and upon receiving the current position a1 after a prescribed timefrom said position information analysis means, corrects said currentposition a1 in said direction of advance measured by said directionmeasurement means and calculates current position display information,and in addition takes the corrected position of said current position a1to be the new reference point.
 7. A pedestrian navigation device fornavigating the route of a pedestrian, comprising: position informationreception means for obtaining current position information; positioninformation analysis means for analyzing said current positioninformation received by the said position information reception meansand calculating the current position; map information storage means forstoring map information; central processing means for calculatingcurrent position display information, based on said current positioncalculated by said position information analysis means, and on said mapinformation stored by said map information storage means; display meansfor displaying said current position display information calculated bysaid central processing means; and, direction measurement means formeasuring the direction of advance; and characterized in that saidcentral processing means takes the current position at the start ofnavigation to be reference point a0, and upon receiving the currentposition ai after a prescribed time from said position informationanalysis means, calculates the direction a0→ai from said reference pointa0 to said current position ai, and (a) if the direction a0→ai isoutside the range of the tolerance angle γ from said direction ofadvance measured by said direction measurement means, uses currentposition display information calculated using said reference point a0without modification; but (b) if the direction a0→ai is within the rangeof the tolerance angle γ from said direction of advance measured by saiddirection measurement means, calculates current position displayinformation using said current position ai, and in addition takes thecorrected position of said current position ai to be the new referencepoint.
 8. The pedestrian navigation device according to claim 6,characterized in that said direction measurement means is an electroniccompass.
 9. The pedestrian navigation device according to claim 6,characterized in that said direction measurement means is a gyrosensor.10. The pedestrian navigation device according to claim 1, characterizedin that said position information reception means obtains currentposition information from a GPS (Global Positioning System).
 11. Aprogram for causing a portable terminal to navigate a pedestrian route,which realizes in the portable terminal the functions of the pedestriannavigation devices according to claim
 1. 12. The pedestrian navigationdevice according to claim 7, characterized in that said directionmeasurement means is an electronic compass.
 13. The pedestriannavigation device according to claim 7, characterized in that saiddirection measurement means is a gyrosensor.
 14. The pedestriannavigation device according to claim 2, characterized in that saidposition information reception means obtains current positioninformation from a GPS (Global Positioning System).
 15. The pedestriannavigation device according to claim 3, characterized in that saidposition information reception means obtains current positioninformation from a GPS (Global Positioning System).
 16. The pedestriannavigation device according to claim 4, characterized in that saidposition information reception means obtains current positioninformation from a GPS (Global Positioning System).
 17. The pedestriannavigation device according to claim 5, characterized in that saidposition information reception means obtains current positioninformation from a GPS (Global Positioning System).
 18. The pedestriannavigation device according to claim 6, characterized in that saidposition information reception means obtains current positioninformation from a GPS (Global Positioning System).
 19. The pedestriannavigation device according to claim 7, characterized in that saidposition information reception means obtains current positioninformation from a GPS (Global Positioning System).
 20. A program forcausing a portable terminal to navigate a pedestrian route, whichrealizes in the portable terminal the functions of the pedestriannavigation devices according to claim
 2. 21. A program for causing aportable terminal to navigate a pedestrian route, which realizes in theportable terminal the functions of the pedestrian navigation devicesaccording to claim
 3. 22. A program for causing a portable terminal tonavigate a pedestrian route, which realizes in the portable terminal thefunctions of the pedestrian navigation devices according to claim
 4. 23.A program for causing a portable terminal to navigate a pedestrianroute, which realizes in the portable terminal the functions of thepedestrian navigation devices according to claim
 5. 24. A program forcausing a portable terminal to navigate a pedestrian route, whichrealizes in the portable terminal the functions of the pedestriannavigation devices according to claim
 6. 25. A program for causing aportable terminal to navigate a pedestrian route, which realizes in theportable terminal the functions of the pedestrian navigation devicesaccording to claim 7.